Project Design And Optimization Research Of Locomotive Cooling Fans Based On Multi-source Constraints

Ventilator is a kind of general machinery widely used in various fields of national economy. Due to low pressure rise, less single energy consumption, ventilator is lack of attention, design theory is not perfect. However, a variety of survey data show that the energy consumed in driving the ventilator accounts for about10%of the total generating capacity, so although single fan energy consumption is less, but in the national production, which occupies a great proportion of the total energy consumption. Therefore, improving the performance and efficiency of the ventilator is extremely important for energy saving.Traditional fan design get the excellent performance of the fan by a lot of experiments and continuous improvement, designers made the ventilator pedigrees aim at different flow and pressure, and select from the pedigrees again when re-applying, or get the corresponding fan through a similar transformation. With China Railway continuously improve its speed and the level of load, the demand of cooling ventilation of the heating elements is also increasing, The fans corresponding to domestic ventilator pedigrees has been unable to satisfy its cooling ventilation requirements, this kinds of fans are mostly dependent on imports now. To improve the design and development capabilities as soon as possible, and replace imports, has become a serious problem now.This paper takes three engineering examples as background, use CFD methods and optimization theory, investigate fan’s sensitivity of structural performance In the case of changing its structure parameters Summarizes the localization of imported fan design experience in the case of reducing speed and stable structure, and apply to the performance improvements of locomotive tractive fan.The first part is a localization design of centrifugal cooling fan for One locomotive bogie. Using CFD method, starting from the design requirements, for the design difficulties, accomplish one-dimensional aerodynamic design,3D modeling, numerical simulation analysis of multi-scheme design according to the basic principle of ventilator; summarizes the sensitivity of the geometric parameters on performance; choose the best program to make the corresponding multi-program volute aerodynamic design, complete modeling and numerical simulation; finally get the optimal design.The second part, take the performance check of centrifugal cooling fan for CKDOA locomotive traction as background, combined with CFD numerical methods, comparing the results of the checking calculated values with the cooling ventilation requirements, the performance does not meet the requirements, the improved design is needed; analysis the results of numerical check and post-processing diagram, according to the basic principles and the sensitivity conclusions of the geometric parameters on performance in the first part, determine the improved design scheme of the fan; complete the multi-programs improve design of the fan.The third part, presents an optimization procedure for a localization problem of axial cooling fan impeller for a high-power locomotives, based on a artificial neural network surrogate model, combined with the three dimensional Reynolds averaged N-S equations. The optimization processes has been conducted with design variables defining the inlet angle, the outlet angle of medial camber line of blade and the setting angle of blade. The efficiency and the static pressure rise as aerodynamic performance parameters have been selected as the objective function for optimizations. The objective function values have been assessed through three-dimensional flow analysis at design points sampled by Random among Discrete Levels sampling in the design space. The design and off-design performance have been both improved in all of the optimum shapes.The three engineering examples above are all satisfy with design requirements and loading operation now. The experience summed can be applied to the future localization of imported fan,and also has a reference design for other types of wind turbine design.